random(4) plugin infrastructure for mulitple RNG in a modular fashion

[Peter Wemm]

On Wed, Aug 7, 2013 at 11:31 AM, David O'Brien <obrien at freebsd.org> wrote:
[..]
>> Please change YARROW_RNG to
>> RNG_NO_YARROW or something similar and keep it in by default.
>
> Given the direction of the patch, I'm don't know how to cleanly inverse
> logic this.

If you were going to go this route you would put "options YARROW_RNG"
into $ARCH/conf/DEFAULTS and let people disable it with 'nooptions
YARROW_RNG'.  'device random' should probably be a default option
alongside it too though given how badly things fail without it.

Especially given:
> * If the kernel doesn't have any random_adaptor adapters present then the
>   creation of /dev/random is postponed until next random_adaptor is kldload'ed.

Postponing can't really be done.  That's a good way to remotely brick
a machine.  I'd be more inclined to have it be a panic offense if
'device random' is present with no sources.
-- 
Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com; KI6FJV
UTF-8: for when a ' just won\342\200\231t do.
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